Bowling alley grinding machine



May 1,1951 'A. E. ZWOBODA ET AL BOWLING ALLEY GRINDING MACHINE Filed Feb. 21; 1947 3 Sheets-Sheet .1

w c Q Q 2. K mm m. 8 g S No i m @m 8 ARTHUR EFLWOBODA DANIEL BENEDICT INVENTORS. ,4

MKQ/v ATTORNEY y 1951 A. E. ZWOBODA ET AL 2,550,749

V BOWLING ALLEY GRINDING MACHINE Filed Feb. 21, 1947 3 Sheets-Sheet 2 ARTHUR e. ZWOBODA DANIEL senemcr INVENTORS.

ATTORNEY y 51 A. E. ZWOBODA ET AL 7 2,550,749

BOWLING ALLEY GRINDING MACHINE Filed Feb. 21, 1947 3 Sheets-Sheet 3 75 /7 ARTHUR EJWOBDDA H l DANIEL BENEDICT J so 80 DINVENTORS.

' ATTORNEY 3. submitted merely as showing a preferred exemplification of the invention.

Referring in detail to the drawing, l denotes an apparatus for the level grinding of a floor or surface member I such as that of a bowling alley or the like. Extending along opposite sides of the member N there are providedsupports |2 which in this particular exemplification may furnish longitudinal troughs l3 or channels of a bowling alley device. Mounted therein are the parallel rails |4 that may be flanged at I4 for securement by screws or nails l 4 to the members l2. Each of these rails I4 is formedwith one or more inclined surfaces, and desirably each of these rails is provided with an upwardly tapered cross section for a purpose hereinafter described. If desired these rails may be arranged .to furnish a suitable level track, and any means well-known in the art may be utilized for this purpose.

Adapted to travel along the rails I4 is an apparatus comprising a carriage having a frame l5 of any suitable size or shape and being desirably of generally rectangular form to constitute a shell which may be open at the top and bottom. Accordingly this frame may comprise a front wall IS, a rear wall l1, and end walls l8. Afiixed to the frame at the four corners thereof are guide plates l9 and 20 which are alined for the vertical square bars 2| to which are afiixed the wheel or roller devices 22. For vertically adjusting each bar 2|, a screw 23 having a large manual head for turning the same is threaded through a corner plate or bracket 24 on the frame and has axial screw engagement at 23 with the bar 2!. Accordingly by turning the screw 23, each roller 22 may be individually vertically moved with respect to the frame I5 whereby the latter may be accurately leveled on the rails l4, thus correcting for any minor deviation of the rails from a true horizontal plane.

To prevent any sawdust or the like from interfering with the true level position of the frame l5, a novel construction and coordination is provided at the rollers 25 and the rails M. The rollers 25 may be conventionally mounted as by an ordinary bracket 26 connected to the bars 2|, these rollers being arranged so as not to project beyond the walls I6 and H. The rollers 25 may be relatively large in diameter and each is furnished with a pair of flanges or discs2'l interconnected by a hub portion 28, thus affording a deep annular recess of ample capacity. The flanges 21 may be relatively thin, but are-strong and rigid. En-

gaged therebetween, the tapered rail |4 projects into the annular recess, the flanges .21 riding on the inclined faces 29of the rail; In fact onlythe inner peripheral edges of the fiangescontact the inclined faces 29 thus affording a line engagement so that any debris that may tend to deposit on the rails or on the rollers will cause little or no interference with a perfectly horizontal travel of the rollers. the flanges 21 tend to remove and'scrape clean the rails.

Extending longitudinally of the frame I5 and transversely of the elongated surface member I is a grinding roller 30 of any suitable construction, preferably of the type having a roll 3| enwrapped in a sheet of flexible grinding material 32, such as sandpaper or the like. The material 32 is re.-

By reason of the inclined faces 29,

leasably snugly secured to the roll 3| as hereinafter described, whereby any other material may also be used as for bufling and polishing and other purposes. The end of the roll 3| may have stub shafts 33 asshown in Fig. 4. .Means is provided 4 on the frame l5 whereby the rotated grinding roller 30 is driven along the floor member I! while adapted to freely fioat up and down accord ing to the initial irregularity in the floor member and under the force of a relatively positive load to thus provide a constant grinding pressure. One construction for this purpose may include the provision of an upright track or guide at each'end of the roller, including members 34 aifixed to the end walls I8 in any suitable man-- ner as by screws 35. These members 34 may be undercut at 33 to furnish confronting recesses forming a guide for a plate or member 3?. The

latter is provided with a suitable bearing 38 for a stub shaft 33 which extends through a vertical slot 39 in its end wall I8. The arrangement is such that the grinding roller 33 moves freely up and down and causes the corresponding movement of the members 31 and 38, with the guide means 34 serving to push the roller along to surface member during the grinding operation. The slot 39 is sufficiently long so as to offer no interference to the up and down movement of the grinding roller, although the slot is closed at its ends.

the grinding roller so that the grinding may not occur beyond a predetermined point in the thick-' ness of the surface member H. a means is utilized which is preferably individually adjustable at the different ends of the roller 30 and which may have a common setting adjustment. Accordingly each plate 37 may have a boss 39 in which is secured a screw 48 having an adjusting nut 4|. Mounted on the end walls 8 is a rod 42 on which are pivoted the parallel arms 43 of a member 44 which is of generally U-shaped form when viewed from above. This member 44 comprises a front bar 45 interconnecting the arms 43, and thus the entire member 44 is swingable as a rigid structure on the pivot rod 42. The arms 43 may be slotted at 45 to receive the rod 42.

Formed on the arms 43 are the depending porthese ears. Since the screws 4|! are freely slidable in the ears, there is provided a collapsible expansible suspension device so that the plates 31 can vibrate up and down without being affected by the member 44. The latter has a suitable stop coaction with the frame l5. For example an angle stop member 48 is secured to the front wall I 6, and an adjustable or suitable screw 49 is threaded through a bar 45 to contact the stop 48. It will thus be seen that there are provided the individual adjustments 4!], 4| at the different ends of the grinding roller 30, and the common adjustment 48, 49 for the grinding roller as a whole so that the latter may not travel beyond a predetermined degree in level grinding the surface member A level gage 59 may be mounted on the bar 45 so as to afford an accurate indication as to whether the grinding roller 30 is horizontal, and this position of the level affords more accurate results than if it were mounted directly on the frame I5.

To permit the grinding roller 39 to be lifted into retracted inoperative position in spaced relation above the surface member II, a suitable means is provided coordinated with the member 44. Thus a rod 5| is journalledin the end walls l8 of the frame, and this rod may have end portions or fingers 52 received in openings 53 of the arms 43, these openings being so arranged as to furnish ample room for angular movement of the In order to limit the downward movement of fingers 52 and to. furnish a cam engagement at the portions 54 to cause the-arms 43, tobe, swung upwardly upon counterclockwise. movement of the fingers .inFig. 3'. Thehandle5z5 may be fixed in any suitable manner to the rod 51, and itsweight serves to hold the fingers 52 in inoperative position. In such position, the fingers 52 are free of the, arms 43 with. sufficient clearance to-permit adjustment. of the member 44 by the set screw 49. The roller may be locked in inoperative position by swinging the fingers 52 through an angle of a little over 90", as limited by the size and shapeof'the opening 53. For driving the roller, any suitable means may. be provided deriving its power from any feasible source. Preferably a motor 56 is mounted on a plate afiixed to. the front; and rear walls lfiand l1: and carrying a pulley 58. A counter shaft 59 is; suitably journalled in the end walls it! as bybearings 6.0., the same carrying a pulley 61 connected by a belt 62 to the motor pulley 58. The countershaft also carries a pulley 63 connected by a belt 64 to relatively large pulley 65 aflixed to the grinding roller 30. This pulley 65 may be some- What larger in diameter than the grinding roller in order'to obtain a suitable speed reduction. An idler pulley 66 is mounted'on a bracket 61 slotted at 68 for the screws 69: that. are affixed to the adjacent end wall whereby the bracket is adjustable up and down. A set screw H1 is threaded through a, lug H on this end wall for adjusting the: pressure on the bracket 51 to adjust the engagement: of the. idler 66 with the belt lit. The arrangement issuch that thebelt 6t does not interfere with free up and down movement of the grinding roller so and exerts only a negligible vertical component of force on the latter.

The grinding roller 3 comprises the roll 3| hereinbefore mentioned, the same being provided with means. for releasably marginally securing the work sheet member 32 in such a manner as to secure the latter taut around the roller while affording a substantially continuous circular grinding face. In other words, there are no nails or obstructions of any" kind forming raised portions in the grinding face. For this purpose the roll 3|. may have a longitudinal opening or groove in which are received one or more rollers 16 suitably spaced in the groove to receive therebetween the marginal portions T! of the workingsheet 32' and to. clamp said marginal portions in position. These marginal portions are thus retained within the groove in an out of the way position and desirably the elements 15 are adapted" for angular movement in different directions for tensioningthe member 32' around the roll 31. theelements is they'may be formed with heads 18 projecting at leastbeyond one end of the roll 3| whereby wrenches can be conveniently applied to simultaneously turn both of these elements. The latter may be locked in set position or they may be so retained by frictional engagement with the roll 31. A simplified bearing means for retaining the elements T6 in place may be provided by forming annular undercuts T9 in. the elements It adjacent to the ends thereof,

these undercuts being'suflicient for the receptionoftheheaddilof a screw 8| which is threaded into the roll 3|. With a sheet 32 cut to the proper size, it is merely necessary" to insert. its, longitudinal; edges between the elements Hi, where upon the latter are turned to feed those edge pore. tions inwardly for clamping the same and for assuring a required degree of tension on the sheet. 32-. Should there be some: inequality in tension:

For turningalong the sheet, slippage may occur at certain points while the elements 16 are turned to finally assure a uniform tension throughout the sheet. Because outer surface portions of the elements I 16 lie along the outer surface of the roll 3|, or at the break in the grinding surface shall not exist at only one point in the periphery of the roller. In other words, the groove 75 may follow a spiral path, in which case the elements 16 may consist of flexible shafting or other flexible material, or such groove may be straight as shown in Figs. 7 and 8. In the latter instance, the groove 82 may be at only a rather small angle to the axis of the roll. and near the center of the roll the elements 16 may be spaced inwardly from: the outer surface of the roll 83, such space ing varying with the angle and the end portions of the elements 16 being in the same relation to the surface of the roll as shown in Figs. 5 and 6. In the rolls 3| and 83, the same may have a weighting core or the body thereof may be made of such material as to furnish the proper gravity pressure for the grinding action of the roller 30. Similarly, the elements l6 may be of any suitable material. While supplemental pressure means such as weights or springs might be utilized, it is preferred that the grinding pressure be exerted solely by a gravity member to afford a constant pressure, and the ideal situation is that the weighting member be embodied in the grinding roll itself so that the latter constitutes an effective fly wheel for a uniform speed and for reduction of vibration. By this arrangement, a highly simple and compact structure is assured.

In use, the temporary lightweight portable rails are secured in position and suitably leveled off if necessary. Then the relatively small lightweight carriage is mounted on the rails with the grinding face of the roller extending across the entire surface member I! which is to be leveled off and the relatively large pulley projecting down into one of the troughs l3. When thus applied, the grindingroller 3H may be above" the surface member H. being so retained by thefingers 5'2.v Now the motor 55 may be started and the arm 55 swung to the position shown in Fig. 3; thus lowering the grinding roller into contact with the surface member II. In this grinding position t e carriage may be manua ly pushed back and forth along the surface memher; or it ma be motor-driven if desired. The grinding ro ler is the only part in contact with the surface member H, and it is free for up and down movement according to initial irregularities in the surface member I! and without inter-.- ference by the drive connections. The pressure for grinding is substantially solely that which is exerted by the weight ofthe grinding roller, and

this is insufficient for any material traction so that the energy thereof is expended mainly in face member is obtained; Where high spots are L encountered in the latter, the sandpaperis not mutilated or torn, but the grinding pressure per vation of grindin is limited so that eventually a true level surface is obtained. Because of the absence of any pressure exerted on the roller by the carriage, vibrations of the roller are not transmitted to the carriage, whereby its true level position is maintained, any tendency to bouncing on the rails i4 being eliminated. Universal adjustment is afforded by means of the individual adjusting screws 23 for the wheels or rollers 25 and by the individual adjusting screws 40 and by the common adjusting stop screw 49. The individual sliding mountings at the ends of the roller afford a motion in perfect parallelism and assure that the grinding roller is always truly horizontal, without being affected by the intermediate parts that might be subject to bending or warping. The rollers 25 and the rails 14 eliminate the effect of any sawdust or the like collecting thereon by affording a line contact and by causing automatic removal of sawdust from the working faces of the rails.

We claim:

1. A device for level grinding the plane surface member'of a bowling alley comprising a relatively light frame supported from beyond both side edges of said plane surface member to travel over and clear the latter at the area to be ground therebetween, a roller sufiiciently weighted for grinding said surface member mounted on said frame to rotate on a horizontal axis, individual means on the frame mounting for said grinding roller adjacent each of its ends to vertically float the roller to conform with irregularities in the surface member, means carried by the frame for driving said roller, and adjusting means including a common member interconnecting the individual supporting means for permitting the roller independent floating movement and for coordinating said individual means to bring the roller out of effective grinding position, and adjustable stop means for the common member.

2. A device of the character described for level grinding the plane surface member of a bowling alley comprising a frame arranged to travel over the surface member so as to clear the latter at the area that is tobe ground, means biased to cause grinding of the surface member under a relatively constant pressure, including a grinding roller, means on the frame mounting the grinding roller, including individual means for engaging the roller adjacent to each of its ends for free up and down travel of the roller according to the irregularities in the surface member,

said roller having a travel path from an operative advanced position in which it projects below the frame in contact with the surface member to an inoperative retracted position above the surface member, the roller being under said constant pressure in its operative position, means for driving the roller while the same moves along said path, adjusting means including individual adjustable means adjacent to each of the ends of the roller for limiting the downward movement of the roller but being free of the latter to avoid interference with the upward movement thereof, and means engaging the adjustable means for raising the latter to lift the roller to retracted position, the adjustable means engaging the roller mounting means to cause such lifting of theroller.

3. A device of the character described for level grinding the plane surface member of a bowling alley comprising 'a frame arranged to travel over the surface member so as to clear the latter at the area that is to be ground, means biased to cause grinding of the surface member under a relatively constant pressure, including a grinding roller, means on the frame mounting the grinding roller, including individual means for engaging the roller adjacent to each of its ends for free up and down travel of the roller according to the irregularities in the surface member, said roller having a travel path from an operative advanced position in which it projects below the.

frame in contact with the surface member to an inoperative retracted position above the sur face member, the roller being under said constant pressure in its operative position, means for driving the roller while the same moves along said path, and adjusting means including individual adjustable means adjacent to each of the ends of the roller for limiting the downward movement of the roller but being free of the latter to avoid interference with the upward movement thereof, said adjusting means including a common member interconnecting the individual adjusting means, and an adjustable stop for the common member.

4. A device of the character described for level grinding the plane surface member of a bowling alley comprising a frame arranged to travel over the surface member so as to clear the latter at the area that is to be ground, means biased to cause grinding of the surface member under a relatively constant pressure, including a grinding roller, means on the frame mounting the grinding roller, including individual means for engaging the roller adjacent to each of its ends for free up and down travel of the roller according to the irregularities in the surface member, said roller having a travel path from an operative advanced position in which it projects below the frame in contact with the sur-' face member to an inoperative retracted position above the surface member, the roller being under constant pressure in its operative position, means for driving the roller while the same moves along said path, and adjusting means including individual adjustable means adjacent to each of the ends of the roller for limiting the downward movement of the roller but being free of the latter to avoid interference with the upward movement thereof, said individual adjusting means engaging with the roller mounting means, the adjusting means having a common member interconnecting the individual adjusting means and serving to hold same in a set position in the operative position of the roller, and means engaging the common means to cause lifting of the adjustable means and hence of the roller mounting means to retract the roller.

5. A device including a traveling carriage, a grinding roller mounted thereon for rotation on a horizontal axis, the carriage having vertical guides positioned adjacent the ends of the roller, bearing containing members for the roller movable along the guides, adjusting means pivoted on the carriage for said bearing containing members, and suspension means inter-connecting the adjusting pivoting means with each of the members, the adjusting means being swingable up and down to raise and lower the roller, stop means for the lowered position of the adjusting lost motion to permit upward vertical movement 9 of the roller without movement of the pivoted means.

6. In a device for level grinding the plane surface of a bowling alley having a grinding roller carriage supported from beyond both side edges of said plane surface member, rails parallelly disposed and spaced from said plane surface member for supporting the carriage, rollers supporting said carriage and riding on said rails, each roller having spaced flanges interconnected by a hub to form a deep annular recess, each rail having opposite longitudinal faces tapering upwardly to provide a portion received in said recess between the flanges short of the hub, said flanges having peripheral edges in line bearing engagement upon said tapered faces of its rail, said flange peripheral edges being the sole bearing between the rail and roller to prevent grinding debris lodging between the flanges and rail faces and upsetting the trim of the carriage.

' ARTHUR E. ZWOBODA.

DANIEL BENEDICT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 939,544 Pickard Nov. 9, 1909 1,051,467 Uppercue Jan. 28, 1913 1,219,670 Schlueter Mar. 20, 1917 1,356,338 Clarke Oct. 19, 1920 1,566,492 McGinness Dec. 22, 1925 2,197,729 Miller Apr. 16, 1940 2,206,671 Muzzo July 2, 1940 2,290,596 Kirchner July 21, 1942 2,316,545 Anderson Apr. 13, 1943 2,375,102 Harris May 1, 1945 2,419,858 Taber Apr. 29, 1947 

